Generally speaking, the present invention pertains to a defrost control system which comprises a timing means including a power driven cam means and electrical switch means opening and closing in response to the cam means and electrically coupled to a heat pump system, and manual switch means electrically connected to selected ones of the electrical switch means.
The present invention pertains to a defrost control system for a heat pump and more particularly to such a system that has a fast defrost cycle and a slow defrost cycle.
Heat pumps have been increasingly used in recent years in heating and cooling of buildings. In the use of such systems, it has been found that during the winter months of operation a heat pump will ice up. The amount of ice that builds up on the evaporator coils will depend on the ambient temperature, relative humidity and wind velocity. These conditions will vary in different parts of the country and even in different locations around the same building. Therefore, it is difficult to determine in advance a proper defrost cycle. The present invention overcomes this problem by providing a means wherein a desired defrost cycle can be selected very easily by the manufacturer, service man or the building owner.